CSP BGA test socket with insert

ABSTRACT

A BGA test socket for use in standard testing and burn-in testing of BGA dice and method for testing such dice is disclosed wherein a die contact insert made of silicon or ceramic using standard IC fabrication technology is used. Through using such an insert, even small scale (pitch) BGA dice can be reliably tested including chip scale packaged (“CSP”) BGA dice. Furthermore, using such an insert allows a conventional socket to be adapted for use with a wide variety of both BGA dice and other varieties. A method for using the device is disclosed which overcomes current static electricity problems experienced in testing CSP BGA dice through closing the test socket before removing the die deposit probe.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 09/941,749,filed Aug. 29, 2001, now U.S. Pat. No. 6,441,628 B1, issued Aug. 27,2002, which is a divisional of application Ser. No. 09/234,593, filedJan. 21, 1999, now U.S. Pat. No. 6,369,595, issued Apr. 9, 2002.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to testing or burn-in sockets andcarriers for semiconductor dice and, more specifically, to an apparatusand method for testing dice which use ball grid array (“BGA”)technology, wherein the socket or carrier includes retaining elements, aforce system, and a removable die contact insert capable of interfacingwith chip scale package (“CSP”) BGA dice received within the carrier.

2. State of the Art

Semiconductor dice are used in virtually every electronic device becausethey are versatile and compact. In fact, each year technology advances,allowing for smaller semiconductor dice and resulting in smallerelectronic devices. Although semiconductor dice are functional at thetime they are created, inherent manufacturing defects, caused by factorssuch as contamination or process variability, are generally expected insome percentage of dice. Dice with inherent manufacturing defects haveshorter lifetimes than dice without such defects and are the largestcontributors to early-life failure rates, or “infant mortality.”Semiconductor manufacturers perform test processes to discover dice withthese types of inherent manufacturing defects and achieve a lowerearly-life failure rate, thereby increasing product reliability.

“Burn-in” refers to the process of accelerating early-life failures.This is done by cycling a semiconductor die through a series of stressesat raised temperature designed to simulate extreme field conditions tocause failure of the die and remove those dice which would haveotherwise failed during early field use. Typical burn-in begins byplacing a semiconductor die package into a socket containing probes orterminals for connecting to all electrical inputs and outputs of thedie. Testing includes pre-burn-in and post-burn-in testing as well asburn-in testing. Many sockets in the art can be used for many forms oftesting and can be either permanently connected to a testing center, ormay act as a carrier which is easily moved and attached to one or moredifferent testing centers for various tests.

One concern in relation to BGA die test sockets is that thesemiconductor die be held in the socket securely enough to maintain avalid testing process through sufficient continuous electricalcommunication between the socket and the die, yet not so securely heldthat the die or its electrical connections are damaged. Examples of testsockets which hold dice with leads in place can be found in U.S. Pat.No. 5,504,436 (Okutsu, 1996), and U.S. Pat. No. 5,088,930 (Murphy,1992). However, these sockets only work to hold the die in place if theelectrical connections are of specific given types, namely extendingleads. Examples of test sockets which hold BGA dice in place can befound in U.S. Pat. No. 5,531,608 (Abe, 1996), and U.S. Pat. No.5,518,410 (Masami, 1996). However, none of these conventional socketscan adequately test CSP BGA dice because the array of terminals in a CSPBGA die is significantly smaller and of finer pitch (i.e., spacingbetween ball centers) than larger scale BGA dice.

A second concern, related to the first, is that the test probes usedwithin a socket have sufficient rigidity and conductive capacity toaccurately test the die. As semiconductor dice and their conductiveelements get smaller, testing of those dice gets more difficult. Forexample, the test probes used to communicate with the BGA die conductiveelement array in U.S. Pat. No. 5,518,410 to Masami and U.S. Pat. No.5,531,608 to Abe, although apparently sufficient for larger scale BGAdice, are not practical for use with CSP BGA dice due to the fine pitcharray of minute balls employed. Using known materials and technology tomake the probes small enough to distinctly test each conductive element(ball) in the array creates test probes which are insufficiently rigidand/or have insufficient conductive capacity. If test probes areinsufficiently rigid, they may bend or break, causing the socket toperform an inaccurate test process. Furthermore, if the test probes haveinsufficient conductive capacity, they may fail or give inaccurateresults. Current technology does not yet permit manufacture of probessmall enough to adequately test CSP BGA dice while maintaining therequired probe rigidity and conductive capacity.

A third concern in relation to test sockets is minimizing the number ofautomated operations required to load and unload a socket, yet maintainsimplicity of socket design. Many conventional sockets and carriers usedfor testing non-packaged and non-encapsulated dice include multipleparts or parts which must be disassembled to insert or remove a die fromthe socket or carrier, thus requiring additional automated steps. Anexample of a carrier with an assembly which must be disassembled toinsert or remove a die is disclosed in co-owned U.S. Pat. No. 5,519,332to Wood et al. (May 21, 1996), herein incorporated by reference. Oneadvantage of using a carrier which must be disassembled, such as thatdisclosed by Wood et al., is there are fewer moving parts than incarriers which do not require disassembly for use and, thus, lessopportunity for mechanical failure. Carriers and sockets in the currentart for testing BGA dice which do not require disassembly to insert andremove dice, although they require fewer automated operations, alsocontain many moving parts. This presents greater opportunity formalfunction and error.

A fourth concern in relation to test sockets used in automated testprocesses is to avoid lids or other socket parts which protrude so farthey interfere with the automated processes. Many sockets in the art fortesting BGA dice include hinged lids which extend well beyond, or above,the socket and thus may be broken off during automated processes. Thisresult is clearly undesired, as it causes delay, causes possibleequipment damage, adds expense for repair, and causes lower die yield.

A fifth concern in dealing with BGA dice in test sockets is the build-upof static electricity on the equipment. Current BGA interface die testprocesses typically include the steps of opening the socket, placing thedie within the socket, releasing the die, then closing the socket.Although this may work for larger scale BGA devices which aresufficiently heavy to overcome the static electricity created betweenthe releasing device and the die, it may not work for CSP BGA die testprocesses. A specific problem experienced more often when testing CSPBGA dice is that static causes the dice to stick to the releasing deviceinstead of remaining in the socket.

It would be advantageous to have a die socket and carrier for use withCSP BGA interface dice which holds the die within the socket, has fewmoving measuring parts, does not require disassembly to insert andremove a die, has a low profile lid and has terminals adequate toaccurately interface with, and test, a CSP BGA die. Furthermore, itwould be advantageous to have a method for testing BGA dice whichovercomes the static electricity problem.

BRIEF SUMMARY OF THE INVENTION

According to the present invention, a test socket assembly is disclosedwherein a removable die contact insert, having terminals of sufficientnumber and disposed to distinctly and accurately interface with, andtest, a CSP BGA die, is disposed within the test socket containingretaining elements and a force system. In general, the inventionincludes a test socket assembly comprising an electrically insulatingbase containing a die contact insert and electrically insulating dieretaining elements which, in cooperation with the base, apply pressureagainst the back side of a BGA die to maintain continuous contactbetween the conductive element array of the die and an array ofelectrically conductive contacts or terminals on the die contact insert.By operating the retaining elements appropriately, the socket may beopened to insert or remove a BGA die from the socket.

In a particular and preferred aspect of the invention, the die contactinsert comprises electric terminals in an array in mirrored orientationto that of the conductive elements of a CSP BGA die and is dimensionedsuch that each conductive element in the array is discretely connectedto the socket in electrical communication sufficient to test the die. Inone embodiment, the die contact insert is removable and interchangeable.In this way, versatility is afforded for multiple conductive elementarray configurations using the same socket. In a more simple embodiment,the die contact insert is affixed to or integral with the base. Inanother embodiment, the electric terminals are wells having electricallyconductive material which extend in conductive paths to a peripheralside of the die contact insert. The paths are then adapted tocommunicate with a testing station or other external station. Such anadaptation allows for mobility and easier connection to the station. Instill another embodiment, the electric terminals of the die contactinsert employ conductive paths to communicate with a correspondingexternal interface integral with the base. Such base external interfacecan then be fit into an existing socket of a burn-in board or otherwiseconnected to a testing station.

In another particular and preferred aspect of the invention, a verticalforce is used to assist in maintaining sufficient continuous electricalcontact between the BGA die terminals and the die contact insert. In onepreferred embodiment, the vertical force is applied by the combinationof an insulating plate suspended and urged toward a retaining element byat least one spring. The die contact insert is disposed between theinsulating plate and the BGA die such that when the socket is closed,vertical force is exerted toward the BGA die, causing it to remain insubstantially continuous electrical contact with the die contact insert.In another preferred embodiment, the retaining element comprisesretention tongs which move between open and closed positions by applyingor releasing pressure on a tong activating frame. In still anotherembodiment, the upper member comprises a clamshell lid, spring-loadedlatch and resilient foam member. When the clamshell lid is moved intothe closed position over a die, the resilient foam member appliesdownward pressure on the die. Yet another embodiment comprises retentiontongs, each having an end affixed to at least one spring urging theretention tong toward the base. Thus, a force is applied from the tongsto any die placed within the socket. The socket is opened and closed byapplying pressure on a tong activating frame which moves the retentiontongs into an appropriate position. In still yet another embodiment, alow-profile lid is pivotally attached to the insert to open or close thesocket and is held closed by a latch. Using a lid allows for a portablerobust package which may be transferred between various test processes.Using a low-profile lid, the robust package may be used in automatedprocesses more easily and with less risk that the lid will be brokenoff.

A method for testing CSP BGA dice is also disclosed wherein the staticelectricity problem experienced in prior art is overcome. According tothe method, a BGA die is brought above a vertical compression testsocket by a die deposit probe surrounded by a sufficiently rigid sleeve.The sleeve is independently lowered to apply a vertical force to aretaining element activating mechanism, thus opening the socket. The diedeposit probe then lowers the die into, and aligned with, the socketcontaining an insert for accommodating that particular CSP BGA die.Instead of then removing the probe as is currently done in the art, thesleeve is withdrawn to close the socket. With the die held in place, thedie deposit probe is then withdrawn. The die is removed by reversing theprevious steps.

Other features, advantages, and objects of the present invention willbecome apparent from a consideration of the drawings and ensuingdescription.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In the drawings, which depict presently preferred embodiments of theinvention and in which like reference numerals refer to like parts indifferent views:

FIG. 1 is a perspective view of an IC socket according to one embodimentof the invention.

FIG. 2 is a top view of a die contact insert according to one embodimentof the invention showing a terminal well array and traces extending toperipheral bond pads.

FIG. 3 is a sectional view of one embodiment of the die contact insertshowing a preferred cross-sectional shape for the wells.

FIG. 4 is a sectional view of one embodiment of the socket with portionsof the base, tong activating frame, plate and die contact insert removedto expose the die contact insert wells. FIG. 4 also depicts a probe andsleeve with the housing partially removed to show socket

FIG. 5 is a view similar to FIG. 4 showing the socket open before a BGAdie is deposited.

FIG. 6 is a view similar to FIG. 4 showing the socket open after a BGAdie is deposited.

FIG. 7 is a view similar to FIG. 4 showing the socket closed afterdepositing a BGA die, but before removing the probe.

FIG. 8 is a view similar to FIG. 4 showing the socket closed afterdepositing a BGA and removing the probe.

FIG. 9 is a view similar to FIG. 4, but illustrating a second embodimentof the socket.

FIG. 10 is a view similar to FIG. 4, but illustrating a secondembodiment of the socket open after depositing a BGA die.

FIG. 11 is a perspective view of a die carrier insert according to athird embodiment of the present invention.

FIG. 12 is a sectional view of the die carrier insert having gull-wingleads disposed in a TSOP socket where a portion of the housing has beenremoved to show the carrier.

FIG. 13 is a sectional view of a die carrier insert according to anembodiment of the invention with a portion of the external casingremoved to show an up-loaded spring and pivot rod attached to therotating lid.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 depicts a preferred test socket 31 according to the invention foruse in BGA die test processes. This socket is operated by applying avertical force or pressure to a tong activating frame 33, thuscompressing the socket 31 and causing retaining elements 35A and 35B(embodied here as tongs 35A and 35B) to pivot outwardly sufficient topermit a BGA die 37 (see FIG. 4) within the socket 31. Preferably,socket guides 39, integral with the tong activating frame 33, areslidably associated with a base 41 having corresponding guide slots 43to ensure the tong activating frame 33 and the base 41 are securelyaligned during operation to prevent tilting, twisting and jamming of thecooperating components. When pressure is released from the tongactivating frame 33, socket closing springs 45 urge the tong activatingframe 33 upward, causing the tongs 35A and 35B to pivot inward.

Conventional vertical compression IC sockets are well known in the art.Specific examples of the mechanics of vertical compression sockets aredescribed in U.S. Pat. No. 5,364,286 to Matsuoka (1994), and U.S. Pat.No. 5,531,608 to Abe (1996), herein incorporated by reference. Nofurther description is believed to be necessary in regard to themechanics and operation of conventional vertical compression sockets.While it is contemplated that some conventional vertical compressionsockets might be modified to work with the insert the invention havedisclosed, conventional vertical compression sockets still maintain theaforementioned disadvantages. According to the present invention, a diecontact insert 47 containing an array of electrical terminal wells 49resides inside a simplified socket 31 to provide support and asufficient communication path between a BGA die 37 (see FIG. 4) and thetest socket 31.

FIG. 2 depicts a top view of a preferred embodiment of the die contactinsert 47 containing the array of terminal wells 49. The die contactinsert 47 with its array of terminal wells 49 can be manufactured assmall as is needed from silicon or ceramic using IC fabricationtechniques known in the art. The terminal wells 49 each preferably havean opening 51 wider than the well bottom 53 to ensure contact when aconductive element configured as a ball 55 (see FIG. 4) from a BGA die37 is placed in the terminal well 49 and accommodate some variance. Thisresults in a terminal well 49 having a cross-section with a trapezoidalshape 61 (see FIG. 3). A trapezoidal cross-section is achievedpreferably with an inverted truncated conical or inverted truncatedpyramidal shape. Although it is preferred, a trapezoidal cross-sectionis not required for accurate testing. Other cross-sectional shapes suchas a square, half circle, rectangle, or other shapes which allow theballs 55 (see FIG. 4) of the BGA die 37 (see FIG. 4) to contact aconductive surface of the terminal well 49 are sufficient. Thedimensions of each terminal well 49 and the spacing (pitch) between eachterminal well 49 are respectively dependent upon the dimensions of theballs 55 used and the spacing (pitch) of the balls 55 on the BGA die 37.No single dimension or array spacing (pitch) is sufficient for everyvariety of BGA die arrangement. However, for any given BGA diearrangement, one of ordinary skill in the art may easily calculate thenecessary dimensions and spacing (pitch) for the terminal well array 49.By using IC fabrication techniques, each terminal well 49 can bemanufactured for electrical communication with the socket 31. One waythis may be accomplished is by lining each terminal well 49 with aconductive material 69 (see FIG. 3) such as a metal. Such techniques arewell known in the art.

As should be clear from the above description, by using IC fabricationtechniques well known in the art, the die contact insert 47 can bemanufactured with many different forms of external contacts andinterfaces. By way of example only, depending on the type of contact orinterface needed for a given socket 31, the die contact insert 47 can bemanufactured simply to have aluminum traces 59 extending to bond pads63, as shown in FIG. 2, which can then be wire bonded out to conductorscarried on the socket body, or have pins 65 receivable in a standardsocket, as shown in FIG. 3, to a lead frame 67 employing J-leads or gullwings, as shown in FIG. 12, or to a larger BGA interface or adaptorboard for connection to a socket made for another device.

FIGS. 4-8 depict the operation of one preferred embodiment of theinvention. According to this embodiment, an IC test socket 31 ismanufactured for use with CSP BGA dice 37 using a die contact insert 47.The die contact insert 47 is supported from its underside by anelectrically insulating plate 71 borne by at least one and preferably aplurality of plate support springs 73 held in place by wrapping eachspring around opposing, aligned spring nodes 75 located on the bottom ofthe electrically insulating plate 71 and on the inside of the base 41directly below the plate spring nodes 75. During operation, a probe 77carrying a CSP BGA die 37 and surrounded by a probe sleeve 79 is broughtabove an empty test socket 31 (FIG. 4). The BGA die 37 is preferablyheld to the probe tip 81 by suction applied through an aperture 83 inthe probe tip 81, but other means known in the art are also adequate.For example, multiple probes having multiple probe tips comprisingvacuum quills may alternatively be used. Once the probe 77 andsurrounding probe sleeve 79 are directly above the socket 31, the probesleeve 79, which is sufficiently rigid and of sufficient dimensions tocontact the tong activating frame 33 and compress the socket 31, appliespressure to the tong activating frame 33 to compress the socket 31 andopen the tongs 35A and 35B (FIG. 5). For reliable operation, the probesleeve 79 of the probe 77 carrying the CSP BGA die 37 preferably extendsbeyond the BGA die 37 to prevent the die 37 from being knocked loosefrom the probe 77 or damaged while the socket 31 is being opened.Furthermore, the dimensions of the tongs 35A and 35B, although notparticularly significant to the operation of the socket 31, are selectedso as to not interfere with the probe 77, die 37, or probe sleeve 79during operation of the socket 31.

Once the socket 31 is compressed and open, the probe 77, which movesindependently of the probe sleeve 79, lowers a CSP BGA die 37 into thesocket 31 so that the array of balls 55 aligns with the mirrored arrayof terminal wells 49 on the die contact insert 47 (FIG. 6). Because theplate support springs 73 urge the electrically insulating plate 71upward, preferably with enough force that the die 37 in a closed socket31 is pressed firmly between the tongs 35A and 35B and the die contactinsert 47, the probe 77 preferably applies pressure to the die 37 oncein the socket 31 to sufficiently depress the plate support springs 73for the tongs 35A and 35B to close over the die 37. To avoid damage tothe plate support springs 73 or other elements of the socket byestablishing a limit for the probe's 77 extension into the socket, platestops 85 are preferable.

After CSP BGA die 37 is securely seated on the die contact insert 47,but before the probe 77 is withdrawn, the probe sleeve 79 is withdrawnand the closing springs 45 urge the tong activating frame 33 into itsrest position. This causes the tongs 35A and 35B to pivot back to theirposition above the BGA die 37 (FIG. 7). The probe 77 is then withdrawn,releasing the die 37 (FIG. 8). With the plate support springs 73 urgingthe plate 71 and die contact insert 47 toward the die balls 55 and thetongs 35A and 35B exerting equal, opposite force against the diesubstrate 87, the die balls 55 are preferably held against the terminalwells 49 in substantially continuous electrical communication throughoutthe test processes. Also, by closing the tongs 35A and 35B beforeremoving the probe 77, any static electric charge built up between theprobe 77 and the die substrate 87 is overcome when the probe 77 iswithdrawn; the die 37 remains in the socket 31.

FIGS. 9-10 illustrate a second embodiment of the invention to show thatalthough it is preferable to have force applied within the socket 31 tohold the die balls 55 against the terminal wells 49 for sufficientlycontinuous electrical communication throughout test processes, suchpressure need not come solely from plate support springs 73 (see FIG. 8)urging the die contact insert 47 toward the tongs 35A and 35B. At leastone other option is to attach coiled tong springs 89 in tension to thetongs 35A and 35B at a point on each of the tongs 35A and 35B such thatwithout any lateral support, such as provided by tong activating frame33 in FIG. 9, the tongs 35A and 35B would rotate away from the die 37.Such coiled tong springs 89 can thereby pull the tongs 35A and 35Bagainst the die substrate 87 to force the die balls 55 intosubstantially continuous electrical contact with the terminal wells 49when the socket is closed. As shown in FIG. 10, when the socket 31 iscompressed, the tong activating frame 33, which moves independently ofthe tongs 35A and 35B, forces the tongs 35A and 35B upward contrary tothe tension provided by the coiled tong springs 89. Due to the manner inwhich the coiled tong springs 89 are attached to the tongs 35A and 35B,the tongs rotate away from the die when tong activating frame 33 reachesa point in relation to the tongs 35A and 35B where lateral support forthe tongs 35A and 35B is no longer provided. When the pressure on thesocket 31 is released, the tongs 35A and 35B are pulled back down intothe socket 31, are again given lateral support by the tong activatingframe 33, rotate back toward the die 37, and again apply pressure to thedie 37.

FIGS. 11-12 depict a third embodiment of the invention wherein a diecontact insert 47 for use in testing CSP BGA die 37, using existinglarger-scale sockets, contains a force mechanism 91 and lid 93 withinthe die contact insert 47. According to this embodiment, a die contactinsert substrate 95, manufactured using IC fabrication techniques, isdisclosed wherein the die contact insert 47 also includes a clamshelllid 93 and spring-loaded latch 97, rotationally spring-loaded so as toclose when released, for holding a CSP BGA die 37 in place for easytransfer of this die contact insert 47 from one test station to another.A probe opening 99 is included in the lid 93 so the lid 93, like thetongs 35A and 35B in previous embodiments, can be closed beforewithdrawing the probe 77 (not shown) to overcome any static electricitybuilt up between the probe 77 and the die 37. The clamshell lid 93 usedin this embodiment also comprises a resilient force system such asspringy foam force mechanism 91 (e.g. an air-filled elastomer), whichapplies pressure to secure the CSP BGA die balls 55 (not shown, see FIG.9) against the array of terminal wells 49 (not shown, see FIG. 9)exposed on the upper surface of the die contact insert substrate 95. Inthe present embodiment, a die contact insert lid adaptor 101 is used toattach the clamshell lid 93 and spring loaded latch 97 to the diecontact insert substrate 95. As can be seen in FIG. 11, the die contactinsert lid adaptor 101 can also be used to provide additional supportand protection for the BGA die 37 by extending the die contact insertlid adaptor 101 across the die contact insert substrate 95, leaving anaperture 103 in which to insert the BGA die 37. As will be obvious fromthe discussion herein, the die contact insert 47 can be manufacturedhaving the terminal wells 49 contained within the die contact insertsubstrate 95, or an additional removable die contact insert can becreated and placed upon the die contact insert substrate 95 foradditional flexibility of design and application.

Thus, an appropriately sized and adapted die contact insert 47 can beplaced in an existing conventional socket 31. FIG. 12 depicts a diecontact insert 47 according to the embodiment described in relation toFIG. 11, but having a lead frame 67 and gull-wing leads and beingdeposited in a conventional TSOP socket 31. The TSOP socket 31 depictedin FIG. 12 includes a socket activating mechanism 107, a socket base 41,and die contact leads 104 in electrical communication with external pins105. By using a die contact insert 47 which comprises a lid 93 and forcemechanism 91, the die contact insert 47 and BGA die 37 can more easilybe transferred between pre-burn-in, burn-in, and post burn-in testprocesses using existing equipment and processes. The die contact insert47 further allows CSP BGA dice 37 to be tested reliably.

FIG. 13 depicts a fourth embodiment of the invention wherein a diecontact insert 47 for use in testing CSP BGA die 37 using existingsockets is also used as a carrier for a CSP BGA die 37 throughout thevarious stages of testing. According to the embodiments shown, a diecontact insert substrate 95 is manufactured using IC fabricationtechniques. To such substrate 95, a rotating lid 109 and latch 115 areattached to allow a CSP BGA die to be deposited onto and removed fromthe die contact insert 47 (not shown, see FIG. 12). As will be clear toone of ordinary skill in the art, various forms of rotating lids 109,latches 115, and external pins 65 may be substituted for those depictedin the embodiment of FIG. 13 without departing from the nature of theinvention. Preferably, the pivot 111 includes an up-loaded pivot spring123 to urge the lid 109 upward above the spring-loaded latches 115 andstop upward movement with a pivot spring stop 125.

It is contemplated that the various elements of this invention are notrestricted to any particular size or shape. For example, although mostconventional sockets in the industry are square or rectangular in shape,suggesting a square or rectangular shaped insert would be mostappropriate, it is contemplated that such inserts need not be square orrectangular, or of similar size to currently known BGA dice. An insertneed only be of a size sufficient to be deposited in a given socket. Theterminal wells, although preferably wells which extend below the surfaceof the insert lined with aluminum, copper or other conductive substancesuch as metal, can also be flat pads made of similar substances whichrest on the surface of the insert, provided the BGA die is sufficientlyheld in place in alignment over the pads by the tongs, or by some otherretaining element or guide.

It is also contemplated that the various interfaces between the insertand different sockets are not restricted to a particular method. Forexample, electronic communication between an insert and a semiconductorsocket can be accomplished using various interfaces including, but notlimited to, pins, leads, BGAs, bond pads with wiring, and direct wiring.It is also contemplated that such an insert may be removable, like theembodiments shown, or fixed to the socket by adhesive or other means.Although it is contemplated that this invention will be of primarybenefit to the art by providing a device and method to reliably test CSPBGA dice, it is intended that this device may also apply to testinglarge pitch BGA dice or other dice for adapting a socket to test adifferent size, interface, or type of die.

As will be clear to one of ordinary skill in the art, one generaladvantage of using an insert within a socket is the ability to adaptexisting sockets for use in testing BGA dice, and testing BGA dice withvarying pitch, ball dimensions and array configurations using the samesocket. As will also be clear to one of ordinary skill in the art, anadvantage of using an insert manufactured of silicon or ceramic is theability to create a durable array of rigid contact terminals of anydesired shape or electronic property using IC fabrication techniqueswhich can withstand the rigid testing processes applied to semiconductordice and provide a compatible coefficient of thermal expansion (CTE) tothe die material. Another advantage is the ability to create a densearray of precise wells for use with CSP BGA dice where other types ofmanufacturing techniques are inadequate. Using an insert such as theones described here, a CSP BGA die can be adapted for use with standardboard pitch, thus overcoming previously experienced testing problems.

Although the invention has been described with regard to certainpreferred embodiments, the scope of the invention is not limited bythese embodiments and is to be defined by the appended claims.

What is claimed is:
 1. A test socket for a chip scale packagedsemiconductor die using a ball grid array interface comprising: avertical compression socket comprising a base and a die retainingelement activating frame wherein the die retaining element activatingframe is configured and positioned such that downward vertical movementof the die retaining element activating frame causes at least one dieretaining element within the vertical compression socket to moverotationally away from the base to an open position, and wherein upwardmovement of the die retaining element activating frame causes the atleast one die retaining element to move rotationally towards the base toa closed position and wherein the at least one die retaining element isconfigured to retain the chip scale packaged semiconductor die withinthe test socket; and a die contact insert disposed upon a die contactinsert support, the die contact insert comprising: a semiconductorsubstrate; a plurality of electrical connections configured to beremovably electrically coupled with an array of balls from the chipscale packaged semiconductor die; and a conductive element electricallycoupled with and extending from each of the plurality of electricalconnections, each conductive element being configured for electricalcommunication with external circuitry.
 2. The test socket of claim 1,wherein the vertical compression socket includes at least one biasingmember disposed between the at least one die retaining element and thebase.
 3. The test socket of claim 2, wherein the at least one biasingmember is substantially in a state of tension while the at least one dieretaining element is in the closed position.
 4. The test socket of claim2, wherein the vertical compression socket includes at least one otherbiasing member disposed between the die retaining element activatingframe and the base.
 5. The test socket of claim 4, wherein the at leastone biasing member is continually in substantial tension and wherein theat least one other biasing member is in compression when the at leastone die retaining element is in the open position.
 6. The test socket ofclaim 1, wherein the die contact insert is removable from the base andreplaceable by another die contact insert.
 7. The test socket of claim6, wherein the plurality of electrical connections includes a pluralityof wells formed in a top surface of the semiconductor substrate.
 8. Thetest socket of claim 7, wherein each of the plurality of wells isconfigured to receive a corresponding one of the array of balls of thechip scale packaged semiconductor die.
 9. The test socket of claim 8,wherein the plurality of electrical connections includes a conductivelining in each of the plurality of wells.
 10. The test socket of claim9, wherein at least one of the plurality of wells exhibits a trapezoidalcross section.
 11. The test socket of claim 9, wherein the at least onedie retaining element includes at least one tong configured and orientedto retain the chip scale packaged semiconductor die by an edge thereof.12. The test socket of claim 11, wherein the at least one tong includesat least two tongs.
 13. A test socket for a chip scale packagedsemiconductor die using a ball grid array interface comprising: avertical compression socket comprising: a base, at least one retainingelement, a retaining element activating frame, at least one biasingmember disposed between the at least one retaining element and the base,at least one other biasing member disposed between the retaining elementactivating frame and the base; wherein the retaining element activatingframe is configured and positioned such that downward vertical movementof the retaining element activating frame causes the at least oneretaining element to move rotationally away from the base to an openposition, and wherein upward movement of the retaining elementactivating frame causes the at least one retaining element to moverotationally towards the base to a closed position, and wherein the atleast one biasing member is continually in substantial tension andwherein the at least one other biasing member is in compression when theat least one retaining element is in the open position; and a diecontact insert disposed upon a die contact insert support, the diecontact insert comprising: a semiconductor substrate; a plurality ofelectrical connections configured to be removably electrically coupledwith an array of balls from the chip scale packaged semiconductor die;and a conductive element electrically coupled with and extending fromeach of the plurality of electrical connections, each conductive elementbeing configured for electrical communication with external circuitry.